L-Ascorbic Acid-g-Polyaniline Mesoporous Silica Nanocomposite for Efficient Removal of Crystal Violet: A Batch and Fixed Bed Breakthrough Studies

CuO Nanorods Immobilized Agar-Alginate Biopolymer: A Green Functional Material for Photocatalytic Degradation of Amaranth Dye

The contamination of water is increasing day by day due to the increase of urbanization and population. Textile industries contribute to this by discarding their waste directly into water streams without proper treatment. A recent study explores the treatment potential of copper oxide nanorods (CuO NRs) synthesized on a green basis in the presence of a biopolymer matrix of agar (AA) and alginate (Alg), in terms of cost effectiveness and environmental impact. The synthesized bio nanocomposite (BNC) was characterized by using different instrumental techniques such as Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), ultra-violet spectroscopy (UV-Vis), scanning electron microscopy-energy dispersive X-ray-elemental analysis (SEM-EDX), transmission electron microscopy (TEM), selected area diffraction pattern (SAED) and X-ray photoelectron spectroscopy (XPS). The optical studies revealed that immobilization of CuO NRs with Alg-Agar biopolymer blend resulted in an increase in light absorption capacity by decreasing the energy bandgap from 2.53 eV to 2.37 eV. The bio nanocomposite was utilized as a photocatalyst for the degradation of amaranth (AN) dye from an aquatic environment under visible light irradiation. A statistical tool known as central composite design (CCD) associated with response surface methodology (RSM) was taken into consideration to evaluate the optimized values of process variables and their synergistic effect on photocatalytic efficiency. The optimized values of process variables were found to be irradiation time (45 min), AN concentration (80 ppm), catalyst dose (20 mg), and pH (4), resulting in 95.69% of dye degradation at 95% confidence level with desirability level 1. The rate of AN degradation was best defined by pseudo-first-order reaction based on the correlation coefficient value (R2 = 0.99) suggesting the establishment of adsorption-desorption equilibrium initially at the catalyst surface then photogenerated ^•O₂^- radicals interacting with AN molecule to mineralize them into small non-toxic entities like CO₂, H₂O. The material used has high efficiency and stability in photocatalytic degradation experiments up to four cycles of reusability.

Experimental Insights into Mesoporous Polyaniline-Based Nanocomposites for Anionic and Cationic Dye Removal

This work presents the preparation of inorganic-organic hybrid nanocomposites, namely three-dimensional polyaniline (Pani)/activated silica gel (ASG) (3D Pani@ASG), their characterization, and in removing application as a potential adsorbent for cationic brilliant green (BG), crystal violet (CV), and anionic Congo red (CR), and methyl orange (MO) dyes. Pani@ASG nanocomposites have been prepared by the in situ polymerization method and characterized using various techniques such as Fourier transform infrared (FTIR), X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) with selected area electron diffraction, thermogravimetric analysis with derivative thermogravimetry, zeta potential analyses, and Brunauer-Emmett-Teller (BET). The scanning electron microscopy (SEM) study confirms the average particle size of the Pani@ASG nanocomposite is in the range of 5 nm. FESEM, TEM, FTIR, and XRD analysis proved the successful decoration of ASG over Pani. The BET result of Pani@ASG shows a mesoporous nature with a pore diameter of less than 3 nm and a surface area of 423.90 m² g^-1. Both SEM and TEM analyses show the proportional distribution of ASG over Pani's surface. The adsorption trend of BG and MO on the studied materials at pH 7 was found as follows: Pani@ASG > Pani > ASG. The highest sorption capacities of MO and BG on Pani@ASG were 161.29 and 136.98 mg/g (T = 298.15 K, and Pani@ASG dose: 0.04 g for MO and 0.06 g for BG), which were greater compared with bare Pani and bare ASG, respectively. The interaction mechanism behind the adsorption of BG and MO dyes onto the Pani@ASG nanocomposite includes electrostatic interaction, π-π interaction, and hydrogen bonding. The mechanistic pathway and the interactions between the targeted dyes and Pani@ASG were further studied using adsorption isotherm, adsorption kinetics, and thermodynamics.

Efficient Removal of Dyes from Aqueous Solution by Adsorption on L-Arginine-Modified Mesoporous Silica Nanoparticles

The use of mesoporous silica modified with L-arginine (Ar-MSNPs) for the removal of ionic dyes from aqueous solutions has been investigated. Several analytical techniques have been used to determine the characteristics of nanoadsorbents. The removal of crystal violet and fluorescein was performed using the batch method to investigate the effects of cultivation pH, initial concentrations of dyes, and exposure time on adsorption efficiency. The optimum adsorption of fluorescein was achieved at pH 2, whereas the optimum adsorption of crystal violet was achieved at pH 13. The equilibrium was established in both systems at 20 min at low concentrations, and approximately 30 min at high concentrations. The equilibrium adsorption data was analyzed using Langmuir and Freundlich isotherm models. The correlation coefficient (R2) values of the isotherms presented the best fit with the Langmuir isotherm. The adsorption kinetic data was fitted with the pseudo second-order model for both systems.

One-Pot Surface Modification of β-Cu2O NPs for Biocatalytic Performance against A-549 Lung Carcinoma Cell Lines through Docking Analysis

The physicochemical approaches and biological principles in bio-nanotechnology favor specially functionalized nanosized particles. Cuprous oxide nanoparticles (β-Cu₂O NPs) of cuprite phase with a little tenorite (CuO) may be very effective in the development of novel therapeutic approaches against several fatalities including A-549 lung carcinoma cell lines. Consequently, the synthesis of β-Cu₂O NPs for the improvement in the therapeutic index and drug delivery application is becoming an effective strategy in conventional anticarcinoma treatment. Hence, surface-enhanced nanosized spherical cuprous oxide nanoparticles (β-Cu₂O NPs) of cuprite phase were successfully prepared using poly(ethylene glycol) (PEG) as an amphiphilic nonionic surfactant and l-ascorbic acid (K₃[Cu(Cl₅)]@LAA-PEG) reduced to cuprites β-Cu₂O NPs via the sonochemical route. Less improved toxicity and better solubility of β-Cu₂O NPs compared with Axitinib were a major reason for producing β-Cu₂O NPs from K₃[Cu(Cl₅)]@LAA-PEG (LAA, l-ascorbic acid, PEG, poly(ethylene glycol) (PEG)). These nanoparticle syntheses have been suggested to influence their cytotoxicity, free-radical scavenging analysis, and reactive oxygen species (ROS) using poly(ethylene glycol) (PEG) and l-ascorbic acid (LAA) as coated and grafted materials due to their dose-dependent nature and IC₅₀ calculations. The surface morphology of the formed β-Cu₂O NPs has been examined via UV-vis spectroscopy, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy with energy diffraction scattering spectroscopy (SEM@EDS), field emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM) analysis. X-ray diffraction (XRD) and Brunauer-Emmett-Teller (BET) surface analysis results confirm the presence of pure cuprite with a very little amount of tenorite (CuO) phase, Dynamic light scattering (DLS) confirms the negative ζ-value with stable nature. Docking was performed using PDB of lung carcinomas and others, as rigid receptors, whereas the β-Cu₂O NP cluster was treated as a flexible ligand.

Studying the Adsorptive Behavior of Poly(Acrylonitrile-co-Styrene) and Carbon Nanotubes (Nanocomposites) Impregnated with Adsorbent Materials towards Methyl Orange Dye

In this study, a polymeric (acrylonitrile-co-styrene) P(AN-co-St) composite was impregnated with adsorbents, such as sulfonated and multiwall carbon nanotubes (MWCNTs), to increase the adsorptive characteristics of the nanocomposite upon the removal of methyl orange (MO) dye under different conditions. A novel nanocomposite copolymer mixture of P(AN-co-St) and SP(AN-co-St) was used. MWCNTs were prepared by a low-cost chemical vapor deposition (CVD) process. Variation in MO adsorption onto the three nanocomposites was examined in an aqueous solution via the batch technique with respect to contact time, initial MO concentration, adsorbent dosage, pH, and temperature. The surface of the nanocomposites was characterized by a scanning electron microscope (SEM), particle size distribution (PSD), Fourier transform infrared (FTIR), and Raman analysis. The experimental data showed that the efficiency of P(AN-co-St)/ MWCNT removal increased under the conditions of an acidic pH (3 and 5) with an agitation speed of 140 rpm, a sorbent weight of 0.01 g, and 20 mg of initial dye. The maximum sorption capacities were 121.95, 48.78, and 47.84 mg g-1 for the P(AN-co-St)/ MWCNTs, SP(AN-co-St), and P(AN-co-St) composites, respectively, as assessed by the Langmuir model. Additional isotherm models, such as the Freundlich, Temkin, and Halsey models, were used to examine the experimental data. A pseudo-second-order model was found to be more fitting for describing the sorption.